Mud ejection control



Sept. 28, 1943.

c. c. DYER l MUD EJECTION coNTRo'LV Filed. May 12. 1941 f .y mw,

Patented Sept. 28, 1943 UNITED- ,sTAT-,EQS' VPATE,

" anotar'v NT vOF MUu'EJEoTioN'ooNTR-OL oiin'tondpyer, Bakersfield,Calif;v Y Application May 12, 1941seria1vN0.v393,1o3 f 6 claims.(01.255- 2si duction of asimple and efficient dissolvable iow' beanwhich is adapted to be `fitted between the sections of the drill rstemas the drill 'stem is being assembled' and lowered into the hole of thewell, to check and' prevent the sudden eX- pelling of mud out throughthe topof the drill stem, the ow bean being adapted to bedissolved afterthe 'stemis in is applied to the well. y y l Another object of thisinvention is'the production of a simple and efficient method of con`trolling the ejection of mud or vother fluid from the upper end of adrill stern as the stem is being vassembled and lowered, and at the sametime providing for a free, unobstructed passage when pressure is appliedto the well.

-Other objects and advantages of the present invention will appearthroughout the following specification and claims.

VIn the drawing: i j' Figurey 1 is a vertical vsectionalview through aconventional well showing a plurality of sections connected to form thestem: Figure 2 is a side elevational View partly in section of one formoi?v dissolvable iiow bean used in connection with'the presentinvention; Y

Figure 3 is a horizontal sectional view taken on line 3--3 of Figure 2;v l l Figure `4 is a sideelevational viewvlpartly in section of -afurther `type of ow bean: l v.

Figure 5 is a vertical sectionaly Viewy through a portion of the stemshowing a still lfurther modified type of `iiow bean; andv Figure 6` isan enlarged topplan view of the type of :dow bean shown in Figure 5.

To form abasis fora proper understanding of the present inventionattention iscalled'to the following description ofthe assembly andoperation of Adevices of a general character to which the inventionrelates.

Modern oil well drilling is preferably donewith rotary equipment;` Thedrill bity generally' a sh-tail, rotates in muchit'he( same manner as acarpenters -auger or a dentistsdrill. The

ystem upon `which the bit operates isv hollow and is .made ofsectionso'r jointsof heavysteel pipe,

position andwhen pressure -sa'nd feet without the rne'ces'sityI of` Asthe drill vis lowered into the well,`rnew joints or drillV pipe areadded and'no metal 'casing is .used inthe hole or'wellexceptfor a shortdistanc'ebelow lthefsurface, 'one type of casing being' 4indicatedat AinvFig'ure 1.` This casing A preferably comprses a large pipehaving'afared collar B at "its Iupper end which extends above V'thesurface C of thek ground and carries a'mud discharge pipe D' leading toa lmud pit; The upper 'end of the casingA preferably extends 'above thesurface C of the ground to prevent surface caving and `ralso to preventthe entrance of surface water into the hole E. Quite ofteny the hole `isdrilled several `thouprovidingl a casing, and inI order `'tovpreventcaving of the walls the hole` is viilled with heavy mud. The upper jointof the Idrill is 'conventionally termed lkelly andfis' squaremorose-section instead yof.

round,` but is hollow. The purpose ofmaking `thefupper joints squareisto facilitate the attachment thereof to the rotary machinery whichI'bores the hole. A heavy-pressure reinforced rubber hose is 'attachedto the top-"of the kelly,

andthe mud is pumped into the drin' pipe, iri- :di-'catd generallyatF inFigure 1, through -this hose from-heavy mud pumps conveniently-located.IThe mud is pumped'down through' the .hollowdrill stem orpipe F tothebc'ttom of the hole through an orifice in lthe conventional drillbit, and this mud work'sits way "up through rthe open holesurroundingthe hollow drill bit `and runs out through the pipe D at the surface.This continuous pumping of mud isconventi'onf ally referred to 'in thetrade as circulationr As'lthe -bit becomes dulled wand wornQf-the bit-is *pulled from the hole and the hollow drill stem, quite oftenthousands of feet in-` length, -is fastened together at intervals withheavy 'threaded-joints`r` known toV the trade as tool joints. 'Whenthestem 4is removed from the hole', these jointsv are detached and standAin the derrick'inV sections. "Afterthe bit has 'been vrernovedfrom thehole E, the bit is'replacedby a new one, andthen the drill pipe islowered by adding a section at a time until the bit yiinally reaches'the' bottom of the hole at which time therotary drillingoperation'begins.` g Y vDuring the drilling operation, the rotary mudwhichV has been circulated in the Well or hole mud, quite often the mudis expelled violently through the open upper end of the drill stem F,thereby filling the derrick door G with mud and covering the drillingmachinery and clothing, as well as the drillers, with mud, andoccasionally causing serious injury to the eyes of employees locatednearby.

It should be borne in mind that While the drill stem F is being lowered,the Kelly joint is detached so that the top round joint of the drillpipe is open. The hollow in the drill'stern in actual practice is fromthree to ve inches in diameter so that a large quantity of mud ordrilling uid can be expelled as the heavy pipe descends into the hole. lY

With the above general description in mind, the essential features ofthe present invention should be quite apparent, and reference is nowmade to the detail features which are embodied in my invention.

By referring to the drawing, and particularly to Figure 1, it will beseen that II) designates the fish-tail bit which is secured-,to thelower end of the lower section of the tool joint or drill collar II, anda second tool joint or drill collar I2 is threaded upon the upper end ofthe joint II. A drill pipe section I3 is connected to the joint I2 bythreaded engagement and a second drill pipe section I4 is connected tothe pipe section I3 by means of a coupling I5. Other sections may beadded until the desired length of drill stem or pipe F is provided as acomplete assembly. U

`A dissolvable flow bean I6 is placed between the bit I and the tooljoint II and a dissolvable flow bean l1 is placed between the tool jointsections II and I2. A dissolvable flow bean I8 is placed between thedrill pipe section I3 and the -tool joint section I2, anda dissolvableflow bean I 9 is placed between the drill pipe sections I3 and I4,suitable flow beans being similarly placed between each of the sectionsmaking Aup the drill `stem F.

It is not contemplated that the application or use of all of these flowbeans may be necessary in any one descent of the drill bit and drillpipe into the well, At the outset, now beans I6, I1 or I8. or any two ofthem, or all three of them, may be used as occasion necessitates. If,after partial descent into the hole, these preliminary flow beans shouldbecome partially dissolved, allowing too much mud to be ejected throughthe top of the drill pipe then additional flow beans I9 may be added tothe tool joints or connections in the drillpipe as becomes necessary.

These dissolvable flow beans are' also adaptable to the lowering ofother well pipe or tubing into the well.

The flow-bean I8 is illustrated in detail in Figure 2, and the flow beanI8 comprises' an annular collar 28 having a reduced neck 2| and arestricted central bore 22 extends longitudinally of the flow bean I8and is preferably located inthe longitudinal center of the bean I8, thebore 22 being of a relatively small diameterfThe flow bean I8 ispreferably formed of soft material such as lime, plaster, stucco. woodstone, plastic wood, unburned clay, low grade Portland cement, or anyother similar material which will gradually dissolve in water, or isgradually dissipated by abrasion. The flow bean I8 isv preferablyvreinforced by means of longitudinally extending metal reinforcing rods23 of a suitable shape to conform to the contour of the bean. These flowbeans illustrated and described may be inset either in the drill collar,the drill joint or in the tool joint of the drill pipe throughout thelength of the stem F, and by being inset at various places in thedrilling mechanism the orifice in the drill pipe or stem F will begreatly reduced at these points from the original size to about 5/8 ofan inch, and this structure will permit the pipe to be lowered into thewell without reducing the time required for the lowering process and atthe same time provide a check to prevent the sudden overflow or gushingof the mud from the upper end of the well.

In Figure 4, there is shown a slightly modified form of the inventionwherein the flow bean Cal comprises a central annular collar 24 havingoppositely extending reduced necks 25 and 26, and a reduced central bore2l projecting longitudinally of the bean. Suitable reinforcing wires orrods 28 are provided to retain the contour of the bean under normalconditions.

In Figures 5 and 6 there is shown a further modified type of thedissolvable bean and in this type the bean comprises an annular disc 29having a plurality of reduced apertures 30 formed therein, the bean 29being clamped between the sections 3l and 32 of the stem F.

' In assembling the device, as shown in Figure l,

the collar of the bean I6 is preferably clamped between the threaded end33 of the bit I0 and the shoulder 34 of the tool joint Il, the neckportion of the bean I6 extending up into the bore of the section I I.The annular collar of the bean I'I is preferably clamped between thethreaded extension 35 of the section Il and the shoulder 36 of thesection I2. The neck portion of the bean Il extends upwardly into thebore of the section I2. The bean I8 is reversed relative to the positionof the bean I'I and the annular collar of the bean I8 is clamped betweenthe lower end of the section I3 and the shoulder 31 of the section I2,the neck 2| of the bean I8 extending downwardly into the bore of thesection I2.

For the purpose of convenience the bean illustrated in detail in Figure4 is preferably placed between the drill pipe sections I3 and III,` thecentral annular collar 24 of the bean I9V is fitted between the abuttingends of the sections I3 and I4, and the oppositely extending necks 25and 26 extend into the respective bores of the sections I3 and ,|4. Thethreaded coupling I5 connects these sections I3 and I4 together, asshown. It should be borne inlmind that the dissolvable beans may beconstructed as to shape to fit the assembly required, and to conform tothe contour in the best possible manner to anchor the beans in positionand at the same time permit the beans to dissolve or to becomedisintegrated under the action of pressure.

It should be borne in mind that as the stern F ls being assembled andlowered into the well, the beans located between vthe sections remainintact. but as soon as the fKelly joint is attached with its pressurehose and pressure is applied by means of a powerful mud pump or pumps,the mud is pumped down through the drill stem F as the bit rotates inthe bottom of the hole. This pressure is generally tremendous and mayreach 2500 pounds, with the pumping of fifty barrels of mud per minute,and under this pressure the beans located between the sections and whichhave been inserted between the sections are cut to pieces anddissipated, thereby rendering the central bore through the structureuniform and restoring the bore to its original-dimensions. These beansillustrated and described constitute a temporary bushing which willdissipate after the drilling bit has been lowered to the bottom of thehole or well and it is quite important that these beans be located atvarious places throughout the length of the drilling equipment. Thesebeans should remain intact until the pressure of the pump is applied, atwhich time the beans will be dissipated.

It should be understood that certain detail changes in the mechanicalconstruction may be employed without departing from the spirit of theinvention, so long as such changes fall within the scope of the appendedclaims.

Any dissolvable material comes within the claim and purpose of thisinvention, and any reinforcement, whether metal, brous or otherwise,that temporarily supports the integrity of the bean, also comes withinthe claim and `purpose of the invention.

Having described the invention what is claimed as new is:

1. A mud ejection control for well drilling apparatus comprising a stemformed of a plurality of sections, and a dissolvable bean carried in thestem, said bean having a restricted bore to permit the gradual flow ofliquid up through the stem as the stem is being lowered into positionwithin the well, and to cause erosion of the bean and the washing out ofthe bean as fluid continues to flow through the sections of the stem.

2. A dissolvable ow bean of the class described comprising a dissolvablebody adapted to be disintegrated under pressure, the body being shapedto be carried within a drill stem, and reinforcing means for maintainingthe shape of the body under normal pressure.

3. A ilow bean of the class described comprising a disc vadapted to becarried within a drill stem, said disc having a plurality of restrictedflow apertures, the disc beingadapted to retain its formation while thestem is being lowered into a well under normal pressure, and theapertures in the bean being adapted to facilitate erosion as liquid owsthrough the disc to restore the diameter of the bore of the stem tonormal size.

4. A method of the class described comprising assembling a string ofpipes out of a plurality ofv pipe sections having at least onedissolvable choke, lowering the string of pipes into a Well, thelowering being rapid enough to cause the string of pipes to be partiallysupported by liquid in the well due to restricted ilow through thechoke, and then Washing out the dissolvable choke to form a fluidpassage through the string of pipes of substantially enlarged minimumcross section.

5. A throttling device for tubular drill pipe, comprising an annularbody of abradable material, means for anchoring said body Within saidpipe, the axial perforation through said body hav-` ing a diametersubstantially smaller than that of said pipe.

pipe.

CLINTON C. DYER.

